The present invention relates to a display device used to display and transmit the load information of a plurality of circuits and a circuit breaker having the functions of measuring, displaying and transmitting the load information of a single circuit.
In the prior art, JP-A-2002-95152 discloses a circuit breaker which includes a current detection means and a voltage detection means built therein and which, having the functions to calculate and transmit the load information of an electrical circuit, is connected with a display device as required.
The circuit breaker disclosed in JP-A-2002-95152, which presupposes the central management of the load information using a personal computer, employs a method of connecting the display device as required. In this method, the communication means such as RS-232C or an infrared ray is used, and therefore the load information of only the measuring instrument connected is displayed.
Also, the provision of two communication circuits with the measuring instruments to display the load information increases the number of normally-unused extraneous communication means with the increase in measurement points, thereby posing a stumbling block to cost reduction.